Fracture Plug

ABSTRACT

A fracture plug having V-shaped recessions in a housing and complementary wedges is disclosed. The V-shaped recessions are broader at a top of the fracture plug and narrower toward the bottom and the wedges are complementary to the V-shaped recessions. The wedges have a similar thickness and radius as the housing and the wedges sit within an envelope defined by an exterior and interior radius of the housing.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present disclosure claims priority to previously filed U.S.Provisional Patent Application No. 62/923,513 entitled “Frac Plug” filedon Oct. 19, 2019 which is incorporated herein by reference in itsentirety.

BACKGROUND

Downhole fracturing has become a common practice in today's oilfield.One important component fracturing operations is plugs, known as fracplugs. Frac plugs are deployed into a well at a certain depth in orderto seal a zone of the well with sufficient strength to withstand thepressures applied during the fracturing operation. There are manyexisting frac plugs in today's market, but many of them are inefficientor expensive. There is a need in the art for an improved frac plugdesign.

SUMMARY

Embodiments of the present disclosure are directed to a fracture plugincluding a cone comprising a complete cylindrical member defining aninterior diameter and an outer diameter, the cone having a conicalsurface, and a packing element surrounding a portion of the conicalsurface and being configured to expand as the packing element is urgedagainst the conical surface. The fracture plug also includes a housingcomprising an incomplete cylindrical member having substantially thesame interior diameter and outer diameter as the cone. A differencebetween the interior diameter and outer diameter defines a thickness ofthe housing in a radial dimension. The incomplete cylindrical memberincludes a V-shaped recession having a proximal narrow portion and adistal broad portion, wherein proximal and distal are defined relativeto the cone. The fracture plug also includes a wedge positioned in theV-shaped recession and being configured to move from the distal broadportion of the V-shaped recession to the proximal narrow portion and toexpand the housing to set the plug in a well. The wedge hassubstantially the interior diameter and outer diameter as the housing.

Further embodiments of the present disclosure are directed to a fractureplug including a housing formed of a cylindrical member having an innerdiameter and an outer diameter. The housing has a V-shaped recessionwith a narrow portion at a first axial end of the housing and a broadportion at a second axial end of the housing. The V-shaped recessiondefines a slope, and the housing has a radial thickness defined betweenthe inner and outer diameter. The fracture plug also includes a wedgepositioned in the V-shaped recession and having at least approximatelythe same inner diameter and outer diameter as the housing, the sameslope as the V-shaped recession, and the same thickness as the housing.Urging the wedge toward the narrow portion of the V-shaped recession inthe housing causes the housing to expand to set the fracture plug.

Further embodiments of the present disclosure are directed to a methodof setting a fracture plug in a well. The method includes positioning afracture plug in the well, the fracture plug comprising a cylindricalhousing with one or more recessions that are broader at a top of thehousing and narrower at a bottom of the housing. The fracture plugfurther comprising one or more wedges positioned in the recessions. Thewedges have a similar thickness and radius as the housing but areshorter in an axial direction than the housing. The method also includesurging the wedges downward along the recessions such that the wedgesexpand the housing radially to set the fracture plug.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a side view of a frac plug according to embodiments of thepresent disclosure.

FIG. 2 is a side view of the frac plug according to further embodimentsof the present disclosure in which the plug has been fully set.

FIG. 3 is an isometric end view of the plug according to furtherembodiments of the present disclosure.

FIG. 4 is an isometric illustration of embodiments of the presentdisclosure directed to a plug including complimentary wedges.

FIG. 5 is a cross-sectional view of the plug of FIG. 4 in a set positionaccording to embodiments of the present disclosure.

FIG. 6 is a cross-sectional view of the plug according to embodiments ofthe present disclosure in which the ball has not yet been seated in theplug.

FIG. 7 is a cross-sectional view of a frac plug having an internal ballseat according to embodiments of the present disclosure.

FIG. 8 shows the plug with a ball in place and the plug set.

DETAILED DESCRIPTION

FIG. 1 is a side view of a frac plug 100 according to embodiments of thepresent disclosure. The frac plug 100 is also referred to herein as aplug 100. For purposes of explanation and not limitation, the plug 100is oriented such that the left-hand side of FIG. 1 is downhole and theright is uphole. It is to be appreciated, however, that in someembodiments the plug 100 can be inverted. The frac plug 100 includes ahousing 102 that is a generally cylindrical piece of material that hassufficient strength to withstand pressures required in a downholeenvironment. The materials of the various components herein can vary,and can include some (or all) dissolvable or degradable components. Thehousing 102 can include buttons 104 on an exterior surface to enhancethe plug's ability to grip an interior surface in a well, such as acasing or an open hole surface.

The housing 102 can be an incomplete cylindrical member, meaning that itdoes not form a complete circle; rather, the housing 102 has a V-shapedrecession. The V-shaped recession has a narrow portion 106 toward theleft of the picture (which may also be a downhole direction) and a broadportion 108 toward the right side. The frac plug 100 can also include awedge 110 sized and positioned within the V-shaped recession such thatwhen the wedge is urged to the left the housing is urged radially andcircumferentially outward, expanding the plug 100 and setting the plug100.

The wedge 110 and housing 102 can have an interior diameter (ID) and anouter diameter (OD) that are substantially coextensive with one another.The housing 102 and wedge 110 can have a complementary cylindrical shapein which the wedge 110 has similar interior contours and exteriorcontours such that the wedge 110 and housing 102 together have a uniformshape.

The frac plug 100 can also include a packing element 112 which can be anelastomeric member. There is also a cone 114 downward of the housing 102which supports the packing element 112 with a conical surface 116 thaturges the packing element 112 outward as the cone 114 and housing 102are moved together during setting. The frac plug 100 can be set using awireline adapter kit (“WLAK”) or other suitable means that urge thewedge downward and the cone upward.

FIG. 2 is a cross-sectional view of the frac plug 100 according tofurther embodiments of the present disclosure in which the plug has beenfully set. The wedge 110 is shown in a fully-deployed position at thefar left, the housing 102 has reached the cone 114 and urged the packingelement 112 onto the cone 114. The housing and the cone can havecorresponding sloped surfaces to facilitate this engagement. It can beseen that the wedge 110 is relatively short when compared to the housing102 and travels approximately twice its length from the unsetrun-in-hole position (shown in FIG. 1) and the set position shown here.

The radius of the housing 102 is expanded slightly as the wedge 110 isdriven downward to set the plug 100. The radius of the wedge 110 can besimilar to the unset radius, the set radius, or an intermediate radiussomewhere between the set and unset radius of the housing 102.

FIG. 3 is an isometric end view of the plug 100 according to furtherembodiments of the present disclosure. The wedge 110 and housing 102engage with one another along a circumferentially-facing surface at anedge of the V-shaped recession, and that edge can have a complimentaryshape. Shown here there is a convex end 120 on the housing 102 and aconcave end 122 on the wedge. In other embodiments the convexity andconcavity can be reversed. In other embodiments the shape can berounded, or have other angled surfaces that correspond with one anotherto facilitate the wedge moving edgewise along the housing and into placeas the plug is set. In some embodiments the surfaces are keyedcorrespondingly.

FIG. 1 shows a single wedge. FIGS. 2 and 3 show two wedges atdiametrically opposite positions. In other embodiments there may bethree, four, or more wedges.

FIG. 4 is an isometric illustration of embodiments of the presentdisclosure directed to a plug 140 including complimentary wedges. Theplug 140 includes female wedges 142 at a distal end of the plug, andmale wedges 144 at a proximal end. The female wedges 142 are narrower ata distal end and wider nearer the proximal end, whereas the male wedges144 are narrower toward the distal end and wider near the proximal end.In this embodiment there are three female wedges and three male wedges.The wedges are sloped in a complimentary manner to allow the wedges toslide relative to one another as the plug is set. The wedges will alsoexpand radially and circumferentially as the wedges are urged together.The plug 140 can include a shear ring 150 that holds the wedges in placeduring transport and run-in-hole and is designed to fail to allow thewedges to move relative to one another.

The female wedges have a packing element segment 146 on a proximal end,and the male wedges 144 also have a packing element 148 on a proximalend. When the plug 140 is set by moving the wedges toward one another,the packing elements will overlap at least partially, and in someembodiments fully to provide a seal. The plug 140 can also includebuttons 152.

The plug 140 includes a cone 154 at the proximal end to which the malewedges 144 are secured. The cone 154 can also serve as a ball seat oncethe plug 140 is set. The ball can be dropped and set on the cone 154 topressure up for a fracturing operation.

FIG. 5 is a cross-sectional view of the plug 140 of FIG. 4 in a setposition according to embodiments of the present disclosure. The maleand female wedges are shown now with the distal end of the female wedgesseparated due to the angle of the wedges. The packing element 148 can beseen here. It can have a profile that includes a first portion 160 onthe outside of the cone, a second portion 162 as the base, and a thirdportion 164 extending into the seat portion. The cone 154 can have ametal-to-metal sealing surface, but the third portion 164 is below toprovide a flexible and secure seal. The packing element on the malewedges can be similar, although not shown to great advantage here.

FIG. 6 is a cross-sectional view of the plug 140 according toembodiments of the present disclosure in which the ball has not yet beenseated in the plug. Pressure for a fracturing operation can be appliedto the ball which urges the ball into the position shown in FIG. 5. Thebuttons are shown engaged with the casing as well due to the settingpressure and the radial and circumferential expansion caused by movingthe wedges toward one another. The plug can be set using a WLAK or anyother suitable mechanism with sufficient force to urge the wedges into aset position.

FIG. 7 is a cross-sectional view of a frac plug 170 having an internalball seat according to embodiments of the present disclosure. The plug170 includes features generally analogous to features of the plug shownin FIGS. 4-6, including female wedges 172, male wedges 174, a firstpacking element 176, a second packing element 178, buttons 180, and acone 182. The interior portion of the male wedges 174 include a seat 184comprised of an inwardly-angled portion configured to seat a ball. FIG.8 shows the plug 170 with a ball in place and the plug 170 set. Theangle and size of the seat can depend on the size of the plug and theball and can vary as needed. The resulting plug is a relatively shortplug which makes for shorter mill times and/or shorterdissolving/degrading times depending on the material and removalmechanism of the plug.

The above is a description of various features and embodiments of thepresent disclosure which are given to explain certain aspects of thedisclosure. Features from various embodiments can be combined togetherwithout departing from the scope of the disclosure. Directionaldescriptions such as up, down, inside, outside, uphole, downhole aregiven for purposes of explanation and not limitation. Certain aspects ofthe plugs shown and described herein can be inverted. The number andangle of components can vary.

1. A fracture plug, comprising: a cone comprising a complete cylindricalmember defining an interior diameter and an outer diameter, the conehaving a conical surface; a packing element surrounding a portion of theconical surface and being configured to expand as the packing element isurged against the conical surface; a housing comprising an incompletecylindrical member having substantially the same interior diameter andouter diameter as the cone, wherein a difference between the interiordiameter and outer diameter defines a thickness of the housing in aradial dimension, wherein the incomplete cylindrical member includes aV-shaped recession having a proximal narrow portion and a distal broadportion, wherein proximal and distal are defined relative to the cone;and a wedge positioned in the V-shaped recession and being configured tomove from the distal broad portion of the V-shaped recession to theproximal narrow portion and to expand the housing to set the plug in awell, wherein the wedge has substantially the interior diameter andouter diameter as the housing.
 2. The fracture plug of claim 1 whereinthe housing includes a convex circumferentially-facing surface withinthe V-shaped recession and wherein the wedge has a corresponding convexsurface.
 3. The fracture plug of claim 1 wherein the housing includes aflat circumferentially-facing surface on a circumferentially-facingsurface within the V-shaped recession and wherein the wedge has acorresponding flat surface.
 4. The fracture plug of claim 1 wherein thehousing includes a keyed circumferentially-facing surface on acircumferentially-facing surface within the V-shaped recession andwherein the wedge has a corresponding keyed surface.
 5. The fractureplug of claim 1 wherein the housing has a first length along an axialdirection and wherein the wedge has a second length along the axialdirection and wherein the second length is less than half of the firstlength.
 6. The fracture plug of claim 1 wherein the housing is rigidlyattached to the cone.
 7. The fracture plug of claim 1 wherein urging thewedge downward toward the cone causes the packing element to move alongthe conical surface of the cone.
 8. The fracture plug of claim 1,further comprising buttons mounted in an outer surface of the housing tofacilitate setting the fracture plug.
 9. The fracture plug of claim 1wherein at least one of the cone, the packing element, the housing, andthe wedge are made of a dissolvable material.
 10. The fracture plug ofclaim 1 wherein the V-shaped recession comprises a first V-shapedrecession and the wedge comprises a first wedge, the housing including asecond V-shaped recession and a second wedge, wherein the first V-shapedrecession and second wedge are circumferentially opposite the firstV-shaped recession and first wedge.
 11. A fracture plug, comprising: ahousing formed of a cylindrical member having an inner diameter and anouter diameter, wherein the housing has a V-shaped recession with anarrow portion at a first axial end of the housing and a broad portionat a second axial end of the housing, and wherein the V-shaped recessiondefines a slope, and further wherein the housing has a radial thicknessdefined between the inner and outer diameter; and a wedge positioned inthe V-shaped recession and having at least approximately the same innerdiameter and outer diameter as the housing, the same slope as theV-shaped recession, and the same thickness as the housing, whereinurging the wedge toward the narrow portion of the V-shaped recession inthe housing causes the housing to expand to set the fracture plug. 12.The fracture plug of claim 11, further comprising: a cone comprising acylindrical member having a conical outer surface with a narrow portionproximate the housing and a wide portion distal relative to the housing;and a packing element between the cone and the housing wherein urgingthe cone toward the wedge and housing causes the packing element toexpand along the conical surface to set the fracture plug.
 13. Thefracture plug of claim 12 wherein the first axial end of the housing isproximate the cone.
 14. The fracture plug of claim 11 wherein thehousing has two V-shaped recessions and two wedges.
 15. The fractureplug of claim 11, further comprising buttons on an exterior surface ofthe housing.
 16. A method of setting a fracture plug in a well, themethod including: positioning a fracture plug in the well, the fractureplug comprising a cylindrical housing with one or more recessions thatare broader at a top of the housing and narrower at a bottom of thehousing, the fracture plug further comprising one or more wedgespositioned in the recessions, wherein the wedges have a similarthickness and radius as the housing but are shorter in an axialdirection than the housing; and urging the wedges downward along therecessions such that the wedges expand the housing radially to set thefracture plug.
 17. The method of claim 16 wherein the fracture plugfurther comprises a conical surface and an expandable packing elementand wherein urging the wedges downward further comprises urging thepacking element upon the conical surface to expand the packing elementto set the fracture plug.
 18. The method of claim 16 wherein the wedgesand recessions have a complementary shape at circumferentially-facingedges.
 19. The method of claim 18 wherein the complementary shapemaintains the wedges radial position relative to the housing as thewedges are urged downward.
 20. The method of claim 16 wherein beforesetting the fracture plug the wedges are in the broader portion of therecession and wherein urging the wedges downward causes the wedges tomove toward along the recessions.